![]() The CFP is a significant achievement but it’s not a silver bullet. Jacklin gives the example of Gothard weir on the River Dove, which the Wild Trout Trust removed in September 2018 at a cost of just £15,000. It all requires technology, infrastructure and therefore expense well beyond what reinstating fish passage on a less complicated bit of river might entail. Then there are the factors relating to the migrating fish themselves: different species need varying flow rates depending on their anatomy and swimming ability. ![]() There are the location constraints: diverting water through the fish pass must not lower the flow through either the canoe slalom course at the adjoining Holme Pierrepont National Watersports Centre or the turbines of a local hydropower operation the EA also needs maintenance access to Holme Sluices. The EA began conducting feasibility studies for the fish pass back in 2013, but it wasn’t until January 2022 that construction began because of the sheer scale and complexity of the project. A fish pass used by eels, trout and salmon on the Whitendale River, Lancashire. ‘We figured something needed to be done but we didn’t have the resources.’ Fast forward more than 40 years and Ward, now on the cusp of retirement, is delighted to be overseeing the completion of a project that finally solves a problem that he first encountered at the start of his career. It was the first time they’d been seen in the river for many, many decades,’ he recalls. ![]() Ward had his eye on a fish pass at Colwick back in the 1970s, when he first became aware of salmon returning to the Trent. The CFP has been a long time in the making. If there’s more energy when they reach the spawning grounds, they can produce more eggs and the spawning will be more efficient, more productive.’ ‘The improvements to the spawning in the Derwent and the Dove and all those tributaries will increase manyfold because we can get fish past Nottingham very quickly. The new pass at Holme Sluices in Colwick will make a big difference, says Ward. All migratory fish are getting to that point and getting stuck.’ The Dove and the Derwent are stunning rivers and they should be really good salmon rivers – the gravel’s there and the habitat’s there. The weirs on the lower Trent, including Holme Sluices, are only passable by migratory fish in very specific flow conditions and this ‘knackers the rest of the Trent. However, man-made barriers remain problematic, explains Scott McKenzie, senior catchment manager at the Trent Rivers Trust. The construction of England’s biggest fish pass at Holme Sluices. The salmon population there is now regarded as self-sustaining, says Jacklin. Small numbers were recorded in the lower Trent in the 1970s, ’80s and ’90s, and the population was bolstered by reintroductions between 19. Water quality improved during the second half of the 20th century, enough that salmon started to bounce back. Historical data on migratory fish are patchy, but net catch records for the Trent are illustrative of the decline: from around 3,000 salmon a year in the 1880s to just six in 1960. ‘Salmon were made extinct by pollution, but they were already on the decline because of the lack of access to their spawning areas from all the barriers,’ Jacklin continues. ![]() Pollution from the industrial centres of Stoke-on-Trent and Birmingham poured downriver until it reached the 80-kilometre tideway, where it was washed to and fro, with disastrous effects. ‘I know we’ve got a pollution scandal going on at the moment, but on the Trent, when you look back into history, today is nothing,’ says Tim Jacklin, a Wild Trout Trust conservation officer with decades of experience in the Trent catchment. The weirs on the lower Trent are only passable by migratory fish in very limited flow conditions. Some fish were able to overcome these barriers – whether by leaping over or wriggling through what were often imperfect constructions of stone or wood – but these tenacious individuals were then beset by a further challenge: appallingly high levels of water pollution, both chemical and thermal. Holme Sluices was built in the 1950s, but the decline of migratory fish in the Trent catchment dates back to the Industrial Revolution, when large weirs were first built to open up the river for trade. ‘There are all sorts of issues with salmon – exploitation at sea, predation, disease – but we’re fixing one here on the Trent,’ says Simon Ward, a fisheries technical specialist with the EA.
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